রসায়ন • IUT • ইসলামিক ইউনিভার্সিটি অব টেকনোলজি ভর্তি পরীক্ষা ২০২২-২০২৩

রসায়ন প্রশ্ন

1. ক

   The presence of different salts of Ca2+,Mg2+ \mathrm{Ca}^{2+}, \mathrm{Mg}^{2+} and Fe2+ \mathrm{Fe}^{2+} in water is termed as hardness of water.

2. খ

   Temporary hardness is due to presence of Cl− \mathrm{Cl}^{-} , NO3−,SO42− \mathrm{NO}{3}^{-}, \mathrm{SO}{4}^{2-} salts of Ca2+,Mg2+ \mathrm{Ca}^{2+}, \mathrm{Mg}^{2+} and Fe2+ \mathrm{Fe}^{2+} in water.

3. গ

   Permanent hardness is due to presence of HCO3− \mathrm{HCO}_{3}^{-} salts of Ca2+,Mg2+ \mathrm{Ca}^{2+}, \mathrm{Mg}^{2+} and Fe2+ \mathrm{Fe}^{2+} in water.

4. ঘ

   Both hardness can be removed by simple boiling of water.